1. Field of the Invention
The invention relates generally to a safe method of controlling tilting of a rail vehicle and more particularly to a control method ensuring a high level of protection against collisions of tilting vehicles.
2. Description of the Prior Art
The increasing need to reduce the travel times of trains on existing tracks has recently led to the development of tilting trains which can negotiate curves at higher speeds. Tilting trains usually have an automatic tilt control system, for example that described in French patent application FR 2 794 707, for precisely adjusting the tilt of the vehicle as a function of the geometry of the track and the kinematics of the vehicle to ensure the greatest passenger comfort when negotiating curves.
However, tilting vehicles raise new safety problems relating to tilting of the vehicle body, which gives rise to risks of colliding with infrastructures alongside the track (posts, tunnel walls, etc.) or with a train on an adjacent track, especially in the event of failure of the automatic tilt control system.
Also, one object of the present invention is to propose a safe method of controlling the tilting of a rail vehicle that improves safety by ensuring that the contour of the rail vehicle remains at all times within a safety gauge, referred to as the OFG (obstacle-free gauge), defined at any point on the track.
To this end, the invention provides a safe method of controlling the tilt of a rail vehicle traveling on a track, in which method different sections of the track are allocated authorized tilt limit values representative of a safety gauge within which the train can tilt without risk of colliding with infrastructures near the track or a vehicle traveling in the opposite direction, and all tilting of the vehicle is prohibited beyond authorized tilt limit values allocated to the track section on which the vehicle is located.
Particular embodiments of the safe tilt control method according to the invention can have one or more of the following features, separately or in all technically feasible combinations:
the vehicle incorporates cars whose tilting is controlled by an automatic control system for tilting said cars as a function of the kinematics of the vehicle and the geometry of the track, and, independently of commands issued by the automatic tilt control system, for each car of the vehicle, all tilting is prohibited beyond authorized tilt limit values allocated to the track section on which said car of the vehicle is located;
tilting of the cars of the vehicle is prohibited beyond authorized tilt limit values by means of mobile mechanical buffers bearing on the chassis of the bogies of the cars and actuated by actuators, the buffers mechanically preventing tilting of the car beyond a particular tilt, the vehicle including a safe onboard automatic tilt protection system preventatively controlling movement of the mechanical buffers on each bogie of the cars as a function in particular of known authorized tilt limit values;
after sending instructions controlling the buffers, the safe onboard automatic tilt protection system checks the positions of the buffers by means of sensors;
tilting of the cars beyond authorized tilt limit values is prevented by a safe automatic tilt protection system on board the vehicle which continuously measures the actual tilt of the cars of the vehicle using sensors, the safe automatic tilt protection system inhibiting any control instruction sent by the automatic tilt control system that would tilt the cars of the vehicle beyond the authorized tilt limit values;
the tilt of the car is zeroed, accompanied if necessary by emergency stopping of the vehicle, if the tilt values measured for a car exceed the authorized tilt limit values for the track section on which the car is located;
the tilt limit values relating to the track section on which the vehicle is traveling are produced from limit tilt indicative values acquired by the tilt automatic protection safety system on board the vehicle from a beacon disposed upstream of the track section;
the limit tilt indicative values acquired on passing beacons for each of the track sections on which the vehicle travels are stored in a memory on board the vehicle and processed by the safe automatic tilt protection system as a function of the known position of the vehicle on the track; and
the limit tilt indicative values transmitted by the beacons correspond to authorized tilt limit values specific to a vehicle of a given type and, if the vehicle traveling on the track is of a different type, the safe automatic tilt protection system on board that vehicle holds vehicle customizing correction coefficients enabling it to calculate authorized tilt limit values suitable for the type of vehicle actually traveling on the track.
The objects, aspects and advantages of the present invention will be understood better from the following description of particular embodiments of the invention, which description is given by way of non-limiting example and with reference to the accompanying drawings.